AFI 11-2C-130v3 - BITS

90 AFI11-2C-130V3 23 APRIL 2012
6.21.2. Icing. Flight into areas of forecast or reported severe icing is prohibited. Prolonged
operation, such as cruise flight or holding, in areas of moderate icing should be avoided.
NOTE: Air Force Weather Agency technical note AFWA/TN 98/002 states that freezing
drizzle is equivalent to moderate icing and freezing rain is equivalent to severe icing. When
freezing fog is forecast or reported, aircrews will confirm with weather agencies what type (if
any) icing is associated with the freezing fog.
6.21.2.1. Do not takeoff under conditions of freezing rain. Do not takeoff under
conditions of freezing drizzle except when aircraft has been properly de-iced/anti-iced
IAW flight manual procedures.
6.21.2.2. Freezing precipitation, snow, freezing fog, or temperatures near 0°C, may cause
ice or frost to accumulate on aircraft surfaces. When an aircraft requires de-icing/antiicing
prior to takeoff, refer to the following:
6.21.2.2.1. Aircrews will only use de-ice and anti-ice fluids listed in their respective
flight manual. Aircrews will be familiar with, and follow all restrictions in their
associated flight manual with respect to anti-ice/de-ice procedures and holdover
times.
6.21.2.2.2. MIL-A-8243 Type I and Type II de-icing fluids do not provide any antiicing
benefit, and therefore do not have holdover times. Information on the removal
and prevention of frozen precipitation is contained in AF T.O. 42C-1-2, Anti-Icing,
De-Icing and Defrosting of Parked Aircraft available at
https://afkm.wpafb.af.mil/a3of. Approved annual deicing/anti-icing holdover tables
are available at the AFFSA/A3OT website: https://afkm.wpafb.af.mil/a3of. The
holdover time begins when anti-icing fluid is first applied and the PIC shall use time,
temperature, and dilution of mixture to determine when times are exceeded and reapply
fluid if required.
6.21.2.2.3. Ice Pellets. Tests have shown that ice pellets generally remain in the
frozen state imbedded in Type IV anti-icing fluid, and are not absorbed by the fluid in
the same manner as other forms of precipitation. Using current guidelines for
determining anti-icing fluid failure, the presence of a contaminant not absorbed by the
fluid (remaining imbedded) would be an indication that the fluid has failed. These
imbedded ice pellets are generally not readily detectable by the human eye during
pre-takeoff contamination check procedures. Therefore, strict adherence to ice pellet
allowance times is required. Approved Ice Pellet Allowance Times are available at
the HQ AFFSA/A3OF website: https://afkm.wpafb.af.mil/a3of.
6.21.2.2.4. In all cases, PICs will ensure a visual inspection of the aircraft is
completed within 5 minutes of departure.
6.21.3. Thunderstorms.
6.21.3.1. Aircrews should avoid flying in areas of recently dissipated thunderstorms and
advected clouds (horizontal movement of clouds caused by wind) downwind of
thunderstorms. Do not fly directly above (within 2,000 feet) thunderstorms or
cumulonimbus clouds. If unable to vertically clear thunderstorms or cumulonimbus
clouds by at least 2000 feet, avoid them by at least: